**4.3 Scenarios**

To prove plausibility of the optimum PNS structure two scenarios were carried out, both for minimum as well as for maximum substrate cost situations. In the first case the maximum structure was reduced by taking away corn availability. With that only five substrate mixtures could be used for biogas production. The second scenario was set up to get an idea how feedin tariffs can influence the outcome of an optimization. Therefore it was not allowed that a network set-up results e.g. in two 250 kWel CHPs if a 500 kWel instead could be taken.
